Automatic stoker.



D. F. CRAWFORD.

AUTOMATIC STOKER.

APPLIGATION'FILED JUNE27,191Q

Patented Mar. 9, 1915.

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AUTOMATIC STOKER.

Specification of Letters Patent.

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Application filed June 27,1910. Serial No. 569,162.

T all eehom it may concern,

Be 1, known that 1, DAVID F.

CRAWFORD, a citizen of the United States,-

residing at Pittsburgh, in the county of Allegheny and will efiectively agitate and feed the fuel in the trough employed; and the provision of a trough and auxiliary feed construction which may be cheaply constructed, and conveniently assembled. Uertain embodiments of the invention are illustrated in the accompanying draWingswherein- I Figure 1 i803. plan view of the trough provided with my improved feed construction,

Figure 2 is a longitudinal section through the trough.

Figure 3 is a section on the line HT-l[ll[ of Fig. 2 and,

Figure 4 is a perspective view of the end of a modified form of feed piston.

The drawings illustrate only the feed trough with the feeding pistons supplied thereto, but it will be understood that the trough is used in the usual way in a furnace, with grates extending along the sides and across the ends thereof. As shown in the drawings, 1 is the body of the feed trough, preferably a casting; 2 and 3 are closure plates for the slots at the bottom of the body portion 1 in which the auxiliary feed pistons reciprocate; 4 and 5 are the auxiliary feed pistons, which feed pistons, as indicated diagrammatically, are operated from an oscillatory shaft 6 by means of the crank arm 7 and the links 8, 9, 10 and 11; 12

is a main feed piston reciprocating in the cylinder 13 at the rear end of the trough; and 14 indicates the lower edge of the water leg of the locomotive furnace to which the apparatus may be applied.

As indicated in ljig. 3,-the auxiliary feed piston 5 is preferably rectangular in cross section, and is provided at its front end with the teeth 15, which teeth have been found to be a desirable addition, astheyserve to break up and agitate the fuel more efi'ectively than a plain piston does.

as indicated. at

The piston 4. is similarly constructed, but in addition has its front end beveled at 16 in order to present a wedged shaped cutting surface, and also has its upper end surface beveled 17. The beveling of these the piston to cut through fuel efiectively' without as sometimes occurs with surfaces enables and agitate the packing the fuel,

a square headed piston. The front piston 5 may be also beveled if so desired, but at this point in the trough the square headed piston is probably more desirable in thata positive forward feed is desired at this point in order to force the fuel out at the end of the trough, while this is not so necessary in case of the rear piston 41. The sheathing of the pistons 4L and 5, instead of allowing such pistons to lie wholly withinthe trough is desirable as with pistons so sheathed there is practically no tendency to carry-the coal backward on the rear movement of the piston which is not the case where the feed members lie wholly within the trough and are not sheathed. The feed pistons angular in cross section have been found to secure a somewhat better feeding effect than the round pistons heretofore proposed for use as auxiliary feeding means.

The use of the removable closure plates 2 and 3 is desirable in that access is thus given to the slots for any machine work necessary, the casting is more readily made the body portion 1, and the parts may be 7 more conveniently assembled than if the parts 2 and 3 were integral with the body portion 1. Other advantages incident to this construction will be apparent to those skilled in the art.

If desired the auxiliary pistons maybe madewith plain rectangular shaped ends as indicated in Fig. 4:, a member 18 bolted tothe top serving in such case as the agitatin means. I

aving thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is the fol I lowing 1. The combination with a feed trough, of an auxiliary feedpiston mounted for re ciprocation longitudinally of the trough through the bottom thereof and having adupon its upper jacent its frontfend an agitatingprojection ace. 7 2. The'combination with a feed. trough,

of an vauxiliary feed piston mounted for're- 5 ciprocation longitudinally of the trough through the bottom thereof and having adjacent its front end a toothed'upper face.

In testimony whereof I. have hereunto signed my name in the presence of the two 

